Calcium carbonate has been heretofore utilized in wide fields, such as of rubber, plastic, paint, ink, sealing medium, paper, pesticide, neutralizer, food additive and cosmetics. Among them, there is a method which utilizes calcium carbonate as a support (carrier) for liquid-form products as illustrated in Patent Literatures 1 and 2 to improve workability.
This method enables a higher concentration of a silane coupling agent or the like to be supported in a powder of calcium carbonate, either alone or in the form of a mixture with a high-liquid-absorptive inorganic filler. For example, in the case where a specific amount of a silane coupling agent or the like is incorporated in rubber, a handling property is improved. However, a limited loading makes it difficult to exhibit the effect of incorporating calcium carbonate.
On the other hand, Patent Literature 3 and others illustrate cases where the supported amount is small. If a specific amount of a silane coupling agent or the like is to be incorporated in rubber, a higher amount of the carrier must be loaded. This lowers a reinforcing property, for example.    Patent Literature 1: International Publication WO 2006/025423    Patent Literature 2: Japanese Paten Laid-Open No. Sho 56-104950    Patent Literature 3: International Publication WO 2004/009711